Method for flameproofing fibers

ABSTRACT

Natural or synthetic fibers are flame-proofed by treatment with an aziridinyl phosphine oxide compound containing an halogen and an acid curing catalyst which is cured to fix the aziridinyl phosphine oxide compound to the fiber.

United States Patent [191 Fujii et a1.

[451 Jan. 15, 1974 METHOD FOR FLAMEPROOFING FIBERS [75] Inventors: Hajime Fujii; Tatsuo Hattori, both of Shin Nanyo, Japan [73] Assignee: Toyo Soda Manufacturing Co., Ltd., Yamaguchi, Japan [22] Filed: Dec. 29, 1971 [21] Appl. No.: 213,537

[30] Foreign Application Priority Data Doc. 29, I970 Japan 45-121416 Dec. 30, 1970 Japan 45-122090 [52] U.S. Cl. 117/136, 117/138.8 B, 117/139.4, 117/141, 117/142, 117/143 R, 117/144,

260/239 EP [51] Int. Cl C09d 1/00 [58] Field of Search l17/136,141, 142,

1 117/143 R, 144, 139.4, 138.8 B; 8/1162, 8/116 P, 191; 260/239 EP [56] References Cited UNITED STATES PATENTS 2,891,877 6/1959 Chance et a1 117/136 Primary Examiner-William D. Martin Assistant Examiner-Theodore G. Davis Att0rney-Norman F. Oblon et al.

[57] ABSTRACT 12 Claims, N0 Drawings METHOD FOR FLAMEPROOFING FIBERS BACKGROUND OF THE INVENTION 1. Field Of The Invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The aziridinyl phosphine oxide used herein should This invention relates to a method for flameproofing 5 ha n f th following structures:

is-hydroxymethyl-phosphonium hydroxide (THPOH),

tris (l-aziridinyl)phosphine oxide (APO), phosphonyl amide (a white powder prepared by contacting ammonia with phosphorus oxychloride), or phosphonoalkyl amide. The flame-proofing activity of these compounds is generally attributable to the phosphor or phosphor and nitrogen and accordingly a relatively large quantity of the flame-proofing agent is required based on the weight of the fabric. For instance, quantities as large as -30 parts of flame-proofing agent per 100 parts by weight fabric have been required to provide adequate flame-proofing effects.

Another difficulty has been the necessity of using a fiber treating composition, usually containing a melamine resin, urea resin, or thiourea resin, with the flameproofing agent to effectively fix the flame-proofing agent to the fibers. However, the combination of the large quantity of flame-proofing agent and the fiber treating composition, can act to severely diminish the physical properties of the fibers, including their tear strength and their tensile strength.

Often the conventional flame-proofing agent is used in combination with a synergist, such as tris (2,3- dibromopropy] )phosphate, tris (1,3- dichloroisopropyl )phosphate tris (2 ,3- dichloropropyl)phosphate, tris (B-bromoethyDphosphate, or tris (B-chloropropyl) phosphate. This combination often results in excellent flame-proofing effects, usually resulting from the interaction of the halogen radical and the phosphor film-forming mechanism, as disclosed in Textile Research Journal 38, 273 (1968). However, such conventional combinations do not possess reactive groups which are reactive with the fibers or which are polycondensable with the fibers, so they do not possess good resistance to washing or drycleaning.

SUMMARY OF THE INVENTION Accordingly, it is one object of this invention to provide a method using flame-proofing agents which will not adverselyaffect thephysical properties of the fiber, including its tensile or tear strengths.

It is another specific object of this invention to provide a method using a flame-proofing agent which will not adversely affect the feel or color tone of the fibers treated.

A further object of this invention is to provide a method using a flame-proofing agent which can be used in relatively small quantities.

A still further object of this invention is to provide a method using a flame-proofing agent which will impart semi-permanent wash resistance and dry-cleaning resistance to the fibers.

These and other objects, as will hereinafter become more apparent, have been achieved by use of an aziridinyl phosphine oxide as a flame-proofing agent.

wherein R represents a halogenoalkyl group or a sodium sulfonate substituted halogenoalkyl group and R represents a halogenoalkylene group or a sodium sulfonate substituted halogenoalkyl group, and R and R are the same or different and each respectively represent hydrogen or an alkyl group and n represents an in teger of 1 or 2.

z r m B G 1 H r. H C o B C l H H m C o w O 0 P l O P N N "m H\ /nm a H\ 2 C C C mi l ll Suitable halogens for the halogenoalkyl or halogenoalkylene groups are chlorine or bromine. The halo- (I)!!! c n m m N l ()Clhllll: ll: 2

(O Cl-hEHi l-h):

ll l

[ l (IJHa C H X X N P ocniondm 1 CII;

(1 n X x (J N)l OClhIK Jlh) 6% i X X I N P O CHr HJJH: c6. 2

32] CH: X X CH l /N P OCHiCH HCH1O P N\ CH: 2 Hz 2 [33] C13: g X X SI /CH N P(OCH:lH( JHCHzO l? N I 2 2 CH1 2 CH1 0 X X CH: I ll 6 N P O CH: HCHCHIO P N CH; 2 H2 2 [35] (11% (H) X X /CH2 (I N) P OCHIHHCHiO P(N l CH: 2 H2 2 as on,

wherein X represents a chlorine or bromine atom. (Hereinafter, these compounds will be referred to by number and the definition of X as X=Cl or X Br.)

These compounds can be used by being dissolved in an organic solvent, by emulsifying, or by solubilizing with a surface active agent.

Where the compounds are used as an aqueous solution without a surface active agent, a portion of the halogen atoms of these compounds should be substituted with a sodium sulfonate group by reacting with Na SO For instance, such substituted substituents of the compound [1] would be as follows:

(Hereinafter, those compounds having substituted sodium sulfonate groups will be referred to by compound number and number of substituent groups. For instance, [1]-2S will refer to compound [1] having two sodium sulfonate groups.)

The aziridinyl groups of these compounds are bonded to reactive groups of the fibers, or are selfpolymerized to form a water and organic solvent insoluble material on the fibers, when the compounds are cured in the presence of an acidic catalyst, e.g., ammonium chloride, ammonium hydrogen phosphate, am-

monium dihydrogen phosphate, ammonium borofluoride, zinc borofluoride, or zinc nitrate. The resulting material provides excellent semipermanent wash resistance, dry-cleaning resistance, and flame-proofing effects.

These compounds may be applied to a wide variety of natural or synthetic fibers including cotton, hemp, silk, wool, polyester, polyacrylonitrile, polyamide, rayon, polyvinylchloride, or polyvinylidenechloride. it may also be applied to paper, wood, etc. Where any hydroxy group containing cotton is used, the wrinkle resistance, shrink resistance and wash and wear properties of the treated cotton will be improved and moreover, the compounds used herein will impart improved antiseptic and fungicidal properties by cross-linking between the aziridinyl groups and cellulose groups of the cotton.

Since halogen containing phosphorus compounds are generally water-insoluble, it is necessary to consider the medium used for applying these compounds. Water may be used. However, it is necessary to emulsify the compound or to solubilize it by use of a suitable surface active agent. Emulsification is enhanced if a portion of the halogen atoms in the flame-proofing agent is substituted with sodium sulfonate groups. In this instance, even though the halogen is decreased, the sulfonate groups also possess some degree of flame-proofing effect, so that excellent flame-proofing effect are still attained.

Various organic solvents may be used to prepare a suitable treating solution; for instance, such solvents as methanol, ethanol, or N,N'-dimethylformamide (DMF), etc.

The curing catalyst may be a conventional acidic catalyst which is used in amounts of 1 20 percent by weight based on the weight of the flame-proofing agent. The catalyst concentration is preferably in the range of l 30 g/l, especially 2 20 g/l. The temperature of the treating bath should preferably be in the range of 0 60C. and more preferably 0 30C. The wet pick-up is preferably 50 98 wt. especially 60 wt. The drying temperature should preferably be from 30 to 150C, particularly 60 100C.

Relatively low curing temperatures can be used as compared with conventional Pad-Dry-Cure Processes, and is preferably in the range of 50 C, particularly 60 120C. This has the important advantage that no poisonous gas will be generated in contrast to conventional systems such as when using THPOH, THPC, phosphonoalkylamide or APO, wherein formaline or hydrochloride gas is generated during condensation, or phosphine gas is generated during curing. Where a surface active agent is used, the amount of surface active agent is usually in the range of 1 20 wt. preferably 1 15 wt.%. The concentration of flameproofing agent in the solvent or water is preferably 5 60 wt.%, and particularly 5 50 wt.

As a typical example of use, 8- 10 parts by weight of the flame-proofing agent per 100 parts of cotton cloth were applied. The treated fabric was then dried at 80C. for 1 5 minutes and cured at 90 C. for 2 20 minutes, and then soaped to bond. The fabric had a wash resistance, dry-cleaning resistance and flame-proofing effects sufficient to pass the test of J ISA 8952-1970. The flameproofing effects of the method of this invention are remarkably higher than those attainable 'by conventional methods using THPC, THPOH, APO or N-hydroxymethyl-S-(dimethylphosphonopropionamide), and the wash resistance and drycleaning resistance effects of the method of this invention are significantly higher than those of conventional methods.

Having generally described the invention, a more complete understanding can be attained by reference to certain specific examples, which are included herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.

Preparation of the aziridinyl phosphine oxide compound Two examples of preparation of the aziridinyl phosphine oxide compounds will now be described:

ll /N P(OCHzCHBrCH2Bt)z CH2 To a mixture of 38.3 g. (0.25 mole) of POCl and 112 g. (0.75 mole) of N,N-diethylaniline (as hydrochloride removing agent) in 100 ml. of methylenechloride, 10.8 g. (0.25 mole) of ethyleneimine was added dropwise at 20 30C. for minutes, and then 109 g (0.5 mole) of 2,3-dibromo-l-propanol was added dropwise at 30C. for 30 minutes, while stirring. The reaction product was washed with 250 ml. of water to remove N,N-diethylaniline hydrochloride, and methylene chloride was stripped at 40C. for 1 hour under reduced pressure, to yield 120 g. of a pale yellow viscous liquid product having the following properties:

P content 5.84%

Br content 61.07%

specific gravity 2.030 (20C.)

infrared spectrum (NACl plate) on aziridinyl ring lnstead of using methylene chloride, other inert solvents such as (.Cl CHCI H CH COOC H benzene or toluene can be used. Instead of the N,N- diethylaniline, other hydrochloride removing agents, such as pyridine, triethylamine, N,N-diethylaniline or picoline can be used.

It is also possible to add dropwise, 2,3-dibromo-l propanol and then to add ethyleneimine dropwise.

lt is also possible to add dropwise a mixture of 0.5 mole of 2,3-dibromo-l-propanol and 0.5 mole of N,N- diethylaniline and then to add dropwise a mixture of 0.25 mole of ethyleneimine and 0.25 mole of N,N'- diethylaniline or in counter order.

It is also possible to add 0.5 mole of 2,3- dibromopropanol, and to add dropwise 0.5 mole of N,N'-diethylaniline and to add dropwise a mixture of 0.25 mole of ethyleneimine and 0.25 mole of N,N- diethylaniline.

820"" based H. N P (O CH1CHgBrCHzBr) CH A mixture of 435.8 g. (2 mole) of 2,3-dibromo-1- propanol, 202.4 g. (2 mole) of triethylamine in 400 ml. of methylenechloride was added dropwise to 274.6 g. (2 mole) OF PCl in 800 ml. of methylenechloride at 5c.-5c. while stirring. 177.2 g. 4 mole); of

ethyleneamine and 404.8 g. (4 mole) of triethylamine were further added dropwise to said mixture for 2.5 hours.

After the reaction, the reaction product was washed with 700 ml. of water to remove triethylamine hydrochloride, and then methylenechloride was stripped at 40C. for 1 hour under a reduced pressure using a rotary evaporator, to yield 597.8 g. of pale yellow viscous liquid, having the following properties:

P content 9.60% Br content 50.3% infrared spectrum 795"" based on aziridinyl ring specific gravity 1.841 (20C.) The solvent, hydrochloride removing agent and method of addition can be modified, as stated above.

EXAMPLES 1 through 22 The above-mentioned compounds [1] through [26] were dissolved in organic solvents, as shown in Table l, and then curing catalysts, as shown in Table I, were added to prepare suitable immersing solutions. Treatable textiles were immersed in the solutions to attain a 60 to percent pick-up. These textiles were dried at 80C. for 5 minutes, and then cured at 110C. for 5 minutes. They were then soaped using an aqueous solution containing 0.25 weight percent of Na CO and 0.25 weight percent of Nissan Maruseru Soap, a product of Nippon Oils and Fats Co., Ltd., while agitating the aqueous solution vigorously at a temperature of C. and a bath ratio of 50 for 20 minutes. Subsequently, the textiles were rinsed with water at 40C and a bath ratio of for 15 minutes.

One group of the treated textiles were continuously cleaned for twenty times using the above-mentioned soaping and rinsing processes. A second group of textiles were treated by dry-cleaning procedures, twenty times, using l,l,2,2-tetrachloroethylene at 50C. and a bath ratio of 50 while agitating vigorously for 20 minutes.

'lhe textiles in both groups were dried and tested by the flame-proofing testing method, JlS (Japanese lndustrial Standard) -A-8952,l970.

The following notes apply to all of the following tables:

In accordance with Japanese Industrial Standard JlS-A-8952/l970, the test sample is a small thickness fabric having a maximum weight of 450 g. per square meter of fabric area; the afterflame is 3 seconds or less; the residual ignited ash time is 5 seconds or less; the carbonized area is 30 cm or less and the frequency of flame contact is 3 times or more. Tests for flame contact frequency are omitted for fabrics which do not form a molten state when contacted with a flame.

The rate of adhesion of the flame-resistant agent is stipulated as to percent, if 10 weight parts of the said agent is adhered to 100 weight parts of untreated fabric. The pick-up rate is stipulated as 70 percent, if 70 weight parts of immersing solution is impregnated into 100 weight parts of untreated fabric.

Tear strength is tested by a Pendulum process using an Ennondorf Testing Machine. The tear strength is measured after finishing, curing, soaping and rinsing, and the test results are compared with the tear strength of the corresponding untreated textiles.

Tensile strength is tested in accordance with the Grab process stipulated by JlS (Japanese Industrial Standard)-Ll068ll964 (Testing method for tensile strength of textile) and its measurement is performed after finishing, curing, soaping, and rinsing. These test results are compared with those obtained with corresponding untreated textiles.

Dry-wrinkle resistance (W+F) is tested in accordance with the Monsanto process and measurements are then made after finishing, curing, soaping and rinsing. These test results were also compared with those obtained using the corresponding untreated textiles.

W in the said formula means longitudinal shrinkage and E means a transversal shrinkage.

EXAMPLES 23 THROUGH 44 Compounds [1] through [16] were emulsified as O/W type emulsion-s, o-r solubilized by mixing 10 weight TABLE 1 Test of Flame Resistance onFlame-Proofing Treatment of (Organic Solvent) SA-89524970 Experiment Fabric Solution Pickup (weight/area) (g/m) Flame-proofing agent Curing catalyst (g/I) Solvent I Cotton (240.5) [1] (150) Zn(BF ),(S) methanol 74.5

2 Cotton (240.5) [2] (150) Zn(BF ),(5) methanol 75.3

3 Hemp (265.4) [1] (150) Zn(BF,) (5) DMF 77.6

4 Cotton (240.5) [3] (150) Zn(BF.),(5) methanol 73.1

5 Cotton (240.5) [4] (150) N1-l,Cl (2.5) DMF 74 6 Cotton (240.5) [5] (150) NH CI (2.5) methanol 72.9

7 Polyamide (175.0) [6] (150) Zn(BF ),(5) methanol 76 5 8 Polyacrylonitrile (232.3) [7] (150) NH BF,(5) methanol 79,8

9 Cotton (240.5) [8] (150) Zn(BF (l) methanol 73.2

10 Wool (160.3) [9] (150) Zn(BF methanol 70.6 11 Polyvinylalcohol (220.5) (150) Zn(BF ),(5) methanol 78.3 12 Cotton (240.5) (11] (150) NH.H,P0, methanol 74.5 [3 Rayon (Cu-ammonium) (133.0) [12] (180) Zn(BF ),(5) DMF 79.3 14 Cotton (240.5) [13] (150) (NH.),HPO (5) ethanol 72.4 Cotton (240.5) [14] (150) (NH,),HP0 (5) methanol 73.8 16 Silk (148.0) [15] .(150) (NH ),HPO,(5) methanol 76.2 17 Cotton (240.5) [16] (150) (NH ),HPO (S) methanol 79.3 18 Cotton (240.5) [I] (75) Zn(BF.),(5) methanol 72.1

19 Cotton (240.5) [2] (75) Zn(BF ),(5) DMF 78,3

1 Wool (160.3) [1] (75) NH,H,PO (10) ethanol 72.9

[2] (75) 21 Polyamide (175.0) [4] (80) Zn(NO;,),(S) methanol 74.5

22 Rayon (Cu-ammonium) (133.0) [12] (75) Zn(BF ),(5) methanol 76.1

Experiment Rate of Add-on Flame resistance after 20 times continuous washing after curing, Remainder After flame period After glow period Carbonized area Number of flame soaping, rinsing (sec.) (sec.) (Char area) (cm) treatments Experiment Flame resistance after 20 times of continuous dry-cleaning NOTE Remainder After flame After glow Carbonized Times period (sec.) period (sec.) area (Char contacting to area) (cm') flame 1 7.6 2.6 4.4 28.4 tear strength, tensile dry wrinkle (F) 21% strength, (F) resistance (W+F) decrease 3.4% decrease 64% increase 7 7.7 2.7 4.7 29.3 4 "tear strength, tensile dry wrinkle (F) 24% strength (F) (\V+F) decrease 2.9% decrease increase NOTF.

Times contacting to flame Flame resistance after 20 times of continuous dry-cleaning After flame After glow Carhonized ('70) period (sec.) period (sec.) area (Char area) (cm) Experiment Remainder 27.8 mixture of solutions of [I] and [2] 29.3 mixture of solutions of [2] and [4] 26.9 mixture of solutions of [l] and [2] 28 9 mixture of solutions of [4] and [6] 29.3 mixture of solutions of [7] and cedures as in Example 1 were carried out.

All of the treated textiles passed the specifications of flame-resistant testing methods in accordance with the Japanese Industrial Standard .llS-A-8952/ 1970. The to prepare suitable immersing solutions. The same protesting results are set forth in Table II.

TABLE [I Solution Curing catalyst (gll) Pickup (36) Rate of Add-on (g/l) after curing,

Flame-proofing agent Test of Flame-Resistance on Flame-Proofing Treatment of SA-89524970 (O/W type emulsion) Experiment Fabric weight/area (g/m') percent of a non-ionic surfactant (Nonipol I00, product of Sanyo Chemical Industry (Kasei) Co., Ltd.) with the flame-proofing agents. The curing catalysts as shown in Table II were added to the resulting solutions I [13] l4] l5] l6] 1 l l l l I l l 0 2 (75) Zn(BF )|(5) 73.6 8.6 (75) Zn(B 4)1(5) 79.6 8.4 (7 (75) Zn(NO,),(5) 76.5 9.3 (75) Zn(BI-,),(5) 73.l 9.6

Flame resistance after 20 times continuous washing Remainder After flame period After glow period Carbonized area Frequency of flame (sec.) (sec.) (Char area) (cm) contact 4] ('ottun (240.5)

42 Wool (I603) 4') I'ulynrnide (l75.())

44 Rayon (Cu-ammonium) (133.0)

Experiment Flame resistance after times continuous wauhing Experiment Remainder (95) After flame period After glow period Carhonized area Frequency of flame (sec.) (sec.) (Char area) (cm) contact' Experiment NOTE Flame resistance after 20 times continuous dry-cleaning Remainder After After Carbonized Frequency (96) flame glow area (Char of flame period period area) (cm) contact (sec.) (sec.)

23 7.9 2.8 4.7 26.0 o/w type emulsion tensile strength, (F) dry wrinkle resistance,

tear strength, (F) 3.7% decrease (W+F)63% increase 3.2% decrease 29 7.9 2.9 4,9 28.3 4 o/w type emulsion, tensile strength, (F) dry wrinkle resistance,

30 8.3 2.4 4.8 26.5 4 tear strength, (F) 32% decrease (W+F)52% increase 27% decrease 3] 7.9 2.7 4.9 25.1 solubilized solution 32 7.3 2.9 4.4 27.2 o/w emulsion 34 8.0 2.4 4.2 26.4 Do. W H

35 7.4 2.7 4.6 23.9 tear strength, (F) tensile strength, (F) dry wrinkle resistance,

24% decrease 3.6% decrease (W+F) 57% increase 36 79 7 4 g Z91; solubilized solution 37 g 2 5 4 4 25 4 o/w type emulsion 40 3,9 2,3 4,8 29,2 Do. mixture of solutions of [1] and [9| 41 7.6 2.6 4.9 26.8 Ill and [21 42 7.4 2.4 4.3 27.0 D [1| and |2|'" 43 11.6 2.9 4.6 28.4 4 [41 and [6! 44 7.7 2.6 4.5 27.9 D0. [l0] and [t2] ""Tear strength. (F) 22% decrease; tensile strength (F) 4. 1% decrease; dry wrinkle resistance, (W+F) 52% increase.

EXAMPLES 45 through 65 mersing solutions. Similar operations as in Example 1 were carried out. All of the treated textiles passed the Flame-resistance Testing Methods in accordance with Japanese Industrial Standard .lIS-A-8952/ 1970. The

45 results are shown in Table 111.

in the said aqueous solutions to prepare suitable im- TABLE m y Test of Flame-resistance on Flame-Proofing Treatment .llSA-8952- l970(Aqueous solution of SO=,Na suhstitucnts of compound 1-16) Solution Fabric Experiment i hl/areaxglm Flame-proofing agent Curing catalyst (g/l) pickup 45 Cotton (240.5) [ll-1S (150) NH,BF,(5) 73.9 46 Wool( l60.3) [21-18 (150) NH.BF (5) 76.3 47 Cotton (240.5) [11-28 (150) NH BF (5) 7l .6 4B Polyamide (175.0) [31-1S (I) NH BF (5) 78.9 49 Hemp (265.4) [51-15 (150) NH,BF (5) 70.4 50 Silk (148.0) [6]-lS (180) NH,BF (8) 76.2 51 Polyacrylonitrile (232.3) [Bl-1S (150) (NH ),HPO.(5) 72.9 52 Rayon (Cu-ammonium) (133.0) [71-15 (150) Zn(BF ),(5) 78.5 53 Cotton (240.5) [91-25 (150) Zn(BF ),(5) 70.5 54 Polyvinylalcohol (220.5) [101-15 (150) Zn(B 4)=(5) 76.6 55 Cotton (240.5) [lll-lS (l50) Zn(BF.),(5) 74.9 56 Cotton (240.5) [121-15 (I50) Zn(NO=),(S) 78.9 57 Acetate Rayon (139.4) [131-lS (I80) Zn(BF.),(l0) 76.3 58 Polyester (149.8) [131-15 (180) Zn(BF ),(l0) 79.2 59 Wool(l60.3) [l4]-lS (I80) Zn(BF (l0) 76.5 60 Cotton (2405) [lSl-lS (180) Zn(BF.),( 10) 74.3 6l Hemp (265.4) [l6I-IS (180) Zn(BF (l0) 78.l 0: Cotton (240.5) 1 1- (.75) Zn(BF ),(5)

TABLE 111 Test of Flame-resistance on Flame-Proofing Treatment .IISA-8952-1970(Aqucous solution of SO,Na substituents of compound 1-16) Solution Fabric Experiment (weight/areaHg/m") Flame-proofing agent Curing catalyst (g/l) picltup (98) 63 Cotton (240.5) 'l5]-1S (75) Zn(BF )(5) 78.8

[41-1S (75) 64 P01yviny1a1coho1(220.5) [31-15 (80) Zn(NO,),(5) 74.5

(131-18 (70) 65 Acetate Rayon (139.4) [6]'1S (75) NH.BF (5) 75,9

Flame-resistance after times continuous washing Experiment Rate of add-on Remainder (96) After flame period After glow period Carbonized area Frequency of flame after curing, (sec) (sec.) (Char area) (cm) contact soaping. rinsing Flame resistance after 20 times continuous dry-cleaning NOTE Experiment Remainder After After Carbnnized frequency flame glow area (Char of flame period period area) (em contact fsee.) (sec.)

45 7.6 2.8 4.3 27.2 "tear strength (F) tensile strength (F) dry wrinkle resistance 31% decrease 3.5% decrease (W+F) 59% increase 46 7.9 2.9 4.5 29.6 Y 47 7.4 2.7 4.5 28.0 48 8.1 2.8 4.6 27.2 4 49 7.9 2.5 4.1 29.2 50 7.5 2.5 4.6 28.8 5 51 8.0 2.9 4.4 27.8 5 52 7.7 2.5 4.9 26.9 5 tear strength (F) tensile strength (F) dry wrinkle resistance 29% decrease 3.9% decrease (W+F) 63% increase 53 7.5 2.6 4.7 25.6 54 7.6 2.8 4.2 29.7 4 55 7.4 2.6 4.5 26.6 56 7.8 2.4 5.0 29.3 57 8.0 2.7 4.1 28.0 58 7.6 2.2 4.7 26.2 5 tear strength (F) tensile strength (F) dry wrink1e resistance 34% decrease 2.6% decrease (W+F) 64% increase 59 7.6 2.3 4.5 26.8 60 7.7 2.9 4.9 28.3 61 7.4 2.8 4.8 29.2 62 7.9 2.8 4.7 29.3 mixture of solutions of [2]-1S and [Ill-IS 63 7.6 2.7 4.9 29.8 [5145 and [91-15'" 64 7.6 2.4 4.3 26.5 5 (ZI-IS and [121-15 65 7.9 2.9 4.6 28.3 161-1S and [21-1S Tear strength (F) 27? decrease: tensile strength (F) 3.1% decrease: dry wrinkle resistance (W+F) 53% increase.

Comparison References 1 through 4 The primary solution consisting of 16 weight parts of tetrakis-hydroxymethyl-phosphonium chloride having a structural formula:

18 weight parts of water and 3 weight parts of triethanol amine and a secondary solution consisting of 9.5 weight parts of trimethylolmelamine, 9.9 weight parts of urea and 45.1 weight parts of water, were prepared. The primary solution and the secondary solution were mixed with each other for minutes before being i 1 (HOCH2)4PCI parts of tris (l-aziridinyl)phosphine oxide having a structural formula:

15 weight parts of thiourea, 3 weight parts of polyethylene softening agent Parmalin-PN, product of Sanyo Chemical Industry Co., Ltd.), 0.2 weight parts of permeating agent (Emulgen-SIO, product of Kawo Atlas Co., Ltd.) and 56.8 weight parts, of water, was prepared. A treatable textile was dipped in the immersing used. The treatable textile was dipped in the solution to 15 Solution at a P P Tale of to Percent, a rate of obtain apick-up of 70 to percent, of to per- 80 to 90 P a rate of no P and a cent, of to percent, and of to. percent. rate of 140 l 150 p l Drymg was effecfed at Curing was effected at for 45 minutes and then 80C. for 5 mmutes and curing at 160C. for 2 minutes. at 1400C for 45 minutes The thermally treated fabric was soaped by use of an The treated textiles were further treated by soaping 20 aqueous Weight Parts of 2- with a bath having a bath ratio of 50, at a temperature CO3 and weight Parts of N f soap, 3 of 90C. for 20 minutes using an aqueous solution con- P f of PP Fats and 0115 w -i using a g taining 0.25 weight percent of Na CO and 0.25 weight f bath f 50 at a telflperaturf f 90 percem of Nissan Maruseru Soap, a product of Nippon while vigorously agitating for 20 m1nutes. Rlnsing was Fats and Oils Co Ltd while agitating vigomufly' The 25 carried out in water at 40 C. and a bath ratloof 100 for textile was then rinsed in a bath having a bath ratio of 15 mmutes; 100 at a temperature of 40C. for 15 minutes. The tex- T fabne SamPles were dred and the Same flame tile was dried and was tested by the Flame-resistance res'stam test as Examples through 21 w e Testing method as previously applied to Examples 1 to formed. The textile sample indicated an adhesion ratio 21. These fabrics indicated an adhesion rate of 45.3 30 of we'ght Percent or more per 100 weight pans of weight percent or more per 100 weight percent of ununtreated textile was only admitted in the specification treated textile as stipulated in 118 (Japanese Industrial of HS (Japanese Industrial Standard)-A-8952/ 1970. Standard )-A-8952/ 1970. The said fabric was cleaned Further, the textile sample which had been treated with 20 times as described above using soap and rinsing. As the APO treating process and the soaping step was clea result, it was found that the add-on rate was low, and 35 aned 20 times using soap and water. the flame-resistant nature was low. It was also found It was found that therate of adhesion was deteriothat textiles which initially passed the tests, did not pass rated and flame-resistancy was also deteriorated. the same tests after 20 times of continuous cleaning The textile sample which initially passed the tests, did steps. These testing results are shown in Table IV. not pass the same tests after 20 times of continuous TABLE IV Test of Flame-resistance on Flame-Proofing Treatment of USA-89524970 (tetrakishydroxymethyl phosphonium chloride) Flame resistance after 1 time curing, soaping, rinsing Reference Fabric Pick-up Remainder After flame After glow Carbonized area Frequency of (weight/area) period (sec.) period (sec.) (Char area) flame contact (pg/m 1 Cotton (240.5) 74.5 20.4 3.8 6.4 38.9 2 Cotton (240.5) 106.3 30.1 3.2 4.9 31.8 3 Cotton (240.5) 132.9 38.9 2.9 4.7 31.3 4 Cotton (240.5) 152.1 45.3 2.7 4.4 26.3

Flame-resistance after 20 times corit inuous washing NOTE Reference After After Carbonized Frequency Remainder flame glow area (Char of flame period period area) (cm) contact (see) (sec) 1 16.8 4.5 7.9 49.8 feelingzsoft; tear strength (F) 60% decrease; tensile strength (F) 6.8%

decrease; dry wrinkle resistance (W-l-F) 34% increase. 2 24.1 3.9 7.4 26.6 feelingzhard; tear strength (F) 78% decrease; tensile strength (F) 20.4%

decrease; dry wrinkle resistance (W+F) 28% increase. 3 32.6 2.8 4.9 36.8 feelingzhard 4 40.2 2.8 4.6 30.9 feelingzhard Comparison References 5 to 8 cleaning An immersing solution which consists of 25 weight The resulting tests are shown in Table V.

TABLE V Test of Flame resistance on flame-proofing treatment olJlSA-8952-1970 (tris (l-aziridinyhphosphine oxide) Flame resistance after 1 time curing. soaping. rinsing Reference Fabric Remainder After flame After glow Carbonized area Frequency of (weight/areaHg/m) Pick-up period (sec.) period (sec.) (Char area) fl tact 5 Cotton (240.5) 63.9 18.0 4.9 7.0 43.2 6 Cotton (2405) 34.3 27.3 2.5 5.2 29.8 7 Cotton (2405) 128.4 42.3 2.7 4.6 26.8 8 Cotton (240.5) 145.6 49.5 2.6 4.2 25.3

Flame resistance after times continuous washing NOTE Reference After After Carbonized Frequency Remainder flame glow area (Char of flame '76) period period area) (cm') contact tsec.) (sec.)

5 14.3 5.8 7.4 50.9 feelingzsoft; tear strength (F) 63% decrease; tensile strength (F) 8.9%

decrease; dry wrinkle resistance (W+F) 29% increase 6 22.1 4.3 5.8 34.5 feelingzslightly hard; tear strength (F) 81% decrease; tensile strength (F) 10.4% decrease; dry wrinkle resistance 27% increase 7 37.4 2.9 5.1 28.5 feeling: hard 8 44.3 2.8 4.7 26.3 feelingthard Comparison References 9 through 12 An immersing solution which consists of 30 weight parts of N-hydroxymethyl-3(dimethylphospho)propine amide having a structural formula of:

ll (CHiOhl CI-IzCHzC ONIIClIzOH These samples were dried and the flame-resistant testing method as in Examples to 21 was carried out. The textile sample indicated an adhesion ratio 01 34.3 weight percent or more in proportion to 100 weight percent of untreated textile and passed the specifications of JIS (Japanese lndustrial Standard)-A- 8952/1970.

The said textile sample which had been treated with N-hydroxymethyl-3-(dimethylphosphono)propione amide and soaping and rinsing and was cleaned 20 times with soap and water. It was found that the rate of adhesion was deteriorated, and flame-resistancy was reduced.

The textile samples which passed the tests initially failed after 20 times of continuous cleaning.

The testing results are shown in Table VI.

TABLE VI Test of Flame Resistance on Flame Proofing Treatment of .llSA 8952-l970 (N-hydroxymethyl-3-(dimethylphosphono)propionamide Flame resistance after 1 time curing, soaping, rinsing Reference Fabric Pick-up (36) Remainder After flame After glow Carbonized area Frequency of (weight/area) period period (Char r flame contact 9 Cotton (240.5) 74.6 l8.9 5.2 6.9 48.9 10 Cotton (240.5) 106.7 27.4 3.9 5.l 35.4 ll Cotton (240.5) 129.3 34.3 2.4 4.6 28.3 12 Cotton (240.5) 155.4 41.0 2.2 4.1 26.5

Flame resistance after 20 times continuous washing NOTE Reference After After Carbonized Frequency Remainder flame glow area (Char of flame period period area) (cm contact (sec) lsec.)

9 15.2 6.4 7.7 51.3 feel: soft; "tear strength (F) 37% decrease; tensile strength (F) 47% decrease; dry wrinkle resistance (W+F) increase 10 24.3 4.8 5.6 40.3 feel: soft; tear strength (F) 45% decrease: tensile strength (F) 8.3%

decrease; dry wrinkle resistance (W+F) 49% increase 1 I 29.5 2.9 4.9 31.2 feelzslightly hard; tear strength (F) 57% decrease; tensile strength (F) 18.1% decrease; dry wrinkle resistance (W+F) 38% increase 12 38.6 2.4 4.4 29.7 feel: hard rate of to percent, to percent, to percent. and to percent.

Drying was carried out at 85C. for 5 minutes and curing at 160C. for 45 minutes.

This textile was treated with a bath having a bath 65 ratio of 50 and at a temperature of 90C. for 20 minutes while vigorously agitating using an aqueous solution containing 0.25 weight percent of Na CO and 0.25 weight percent of Nissan Maruseru Soap, product of Nippon Fats and Oils Co., Ltd.

Practical Examples 66 94 The compounds from [16] to [36] were dissolved in the organic solvents shown in Table VII and the curing catalysts shown in Table I were added. The fabrics to be treated, as shown in Table VII, was soaked in the liquid (padding), their pick-up being 60 80 percent, and were dried up to 5 minutes at 80C. After that, curing was performed for 5 minutes at 1 10C. Each cloth treated by heat was stirred vigorously for 20 minutes at 90C. with a liquor ratio of 50 using a water solution containing 0.25 wt. Na CO and 0.25 wt. Maruseru soap (product of Nippon Yushi K.K., Nissan Marusenu Soap), and then rinsed for minutes with water at C. with a liquor ratio of 100.

One group was subjected to washing with soap and water 20 times, and another group was dry-cleaned 20 times using Perklene (perchloroethylene) as a drycleaning solvent, stirred vigorously for 20 minutes at C. with a liquor ratio of 50. Both groups were dried and the flame-resistance tests of J1S-A-8952-l970 were executed.

As a result, as shown in Table V11, low add-on percentages were obtained, and all of the fabrics passed the standards.

When 10 parts were adhered to 100 parts'of untreated cloth, it is called an add-on percentage of 10 percent. In the case of pick-up, if parts of soaking liquid is picked up by 100 parts of untreated cloth, it is referred to as a pick-up rate of 70 percent. The test fabrics were measured by the Monsanto method after curing, soaping and rinsing, and compared with the untreated cloth. They were then measured by the Grab 10 method of JIS L1068-1964 after curing, soaping and rinsing and compared with untreated cloth. They were further measured by the Pendulum method using an Ermendorf type tester after curing, soaping and rinsing and were compared with untreated cloth.

TABLE VII Test of Flame Resistance on Flame-Proofing Treatment of .l1SA8952-1970 (organic solvent) Solution Experiment Fabric (weight/area(g/m) Flame-proofing Catalyst for Curing (g/l) Solvent Pick-up ('71:)

agent (g/l) 66 Cotton (240.5) (16]-Br(l50) Zn(BF ),(5) ethanol 76.0 67 Hemp (265.4) [16]-Cl(150) Zn(BF ),(5) methanol 74.3 68 Cotton (240.5) [l7]-Br(l5()) NHBFJlO) methanol 79,8 69 Polyvinylalcohol (220.5) [17|-C1(180) NH.BF.(5) ethanol 76.7 70 Polyacrylonitrile (232.3) [18l-Br(150) (NH ),HPO (10) ethanol 69,3 7| Cotton (240.5) ll9l-Br(l50) Zn(NO,) (5) DMF 78.6 72 Polyamide (175.0) [20|-Cl(150) NH H,PO4(10) methanol 73.0 73 Rayon (Cu-ammonium) (133.0) (21]Br(l50) Zn(BF ),(5) DMF 70.4 74 Cotton (240.5) |22|-Br(l50) Zn(BF4)=(5) ethanol 67.1 75 Acetate Rayon (189.4) [22|-Cl(180) (NH HPO 10) ethanol 75.2 76 Staple fiber (143.6) I23]-Br( 150) Zn(NO=) (5) methanol 70.5 77 Polyvinylidenc chloride (221.8) I24]-Br(l50) (NH HPO (10) ethanol 79,4 78 Silk (148.0) l25]-Br(150) Zn(BFi)=(5) methanol 73.6 79 Wool (160.3) [25]-Br(150) (Nl l );fl "161113001 70.1 80 Cotton (240.5) [26]-Br(180) Zn(BF4)z(5) methanol 77.7 81 Modacryl (191.4) [27]-Br(180) NHJrnPo methanol 65.6 82 Polyester (149.8) [28]-CI(150) Zn(BF|):(5) ethanol 760 83 Polyamide (175.0) [29]-Br(150) NH BF (10) ethanol 75,5 84 Cotton (240.5) [30]-C|(150) NH CL(l0) DMF 76,2 85 Hemp (265.4) [31 ]-Br(150) Zn(NO=),(5) DMF 78,1 86 Cotton (240.5) [32]C1(1S0) Zn(NO,),(5) methanol 71,5 87 Polyvinylalcohol (220.5) [33]-Br(150) NH BF (IO) ethanol 74,3 88 Silk (148.0) [34]-Br(150) Zn(BF )=(5) ethanol 76,0 89 Cotton (240.5) [3S]-Cl(150) NH BF (5) methanol 73.2 90 Acetate Rayon (189.4) [36]-Br(150) Zn(BF (5) DMF 75,6 91 Cotton (240.5) [16]-Br(75) (NH HPO (1O) methanol 74,3

[17]-Br(75) 92 Cotton (240.5) [16|-Br(75). Zn(NO;),(5) methanol 76.6 [l7]-Br(75) 93 Polyvinylaleohol (220.5) [16]-C1(75) Zn(BF ),(5) methanol 71.5

I l8|-Cl(75) )4 Hemp (265.4) l19]-Br(75) NH BFAS) methanol 78,2

IZUI-Br (75) Flame resistance after 20 times continuous washing Eperiment Rate of Add-on Remainder After flame period After glow period Carbonized area Frequency of flame after curing. (see) (sec) (Char areaflcm) u m seeping. rinsing Flame resistance after 20 times continuous washing Experiment Rate of Add-on Remainder (712) After flame period After glow period Carbonized area Frequency of flame after curing, (Char contact soaping. rinsing Flame resistance after times continuous dry-cleaning NOTE Experiment After After Carhonized Frequency R i d flame glow area (Char of flame 0 period period area) (cm) ontact (sec) (sec.)

67 7.3 2.4 4.5 28.9 26% decrease; 5.7% decrease; 56% increase 71 7.6 2.9 4.0 29.0 24% decrease; 3.1% decrease; 59% increase 74 7 6 if] 4 265 26% decrease: 3.5% decrease; 64% increase 9] 7.2 3,0 4.6 27.7 solution of mixture of [16]-Br and [I7l-Br 92 7.] 2.3 4.7 26.4 solution of mixture of [16]-Br and [I8l-Br 93 8.0 2.7 4.6 26.0 5 23% decrease; 3.8% decrease; "61% increase 94 7.2 2.5 4.8 29.3 solution of mixture of [16]-Br and [l8]-Cl solution of mixture of [l8l-Br and [20]-Br Practical Examples 95 124 proofing agents. The curing catalysts shown in Table 11 were added to make a soaking liquid. The same opera- 55 tions with Practical Example 66 were performed. Each cloth which was treated, passed the flame-resistance tests of JIS-A-8952-1970.

The compounds from [16] to [36] were made soluble or emulsified in an O/W type emulsion by employing non-ionic surface active agents (the Sanyo Kasei K- .K.s product, Nonipol of 10 wt. to flame- TABLE V111 Test of Flame Resistance on Flame-Proofing Treatment of J1SA-8952-l970 (O/W Type Emulsion) Solution Experiment Fabric (wcightIarca(g/m) Flame- Catalyst for curing (g/l) Solution Pick-up Rate of Add-on after proofing agent curing, soaping.

(g/l) rinsing ('17) 95 Cotton [l6]-Br( 1S0) Zn(BF ),(5) O/W emulsion 75.6 8.6 96 Cotton ll6]-Cl(l50) Zn(BF,),(5) 74.7 8.8 97 Polyacrylonitrile {l7]-Br( Zn(BF (5) 79.6 8.4 98 Cotton [17]-Cl(180) NH Cl(l0) 77.8 8.7 99 Cotton [18]-Br(150) Zn(BF ),(5) 72.7 9.0 8.6

100 Acetate Rayon [19]-Cl(l50) NH BF l0) 76.9

Comparison Example 13 The two types of liquids, i.e., Liquid No. l consisting of 16 parts of tetrakis hydroxymethyl phosphonium Chloride:

(HO CH2 4P C1 18 parts of water and 3 parts of triethanolamine and Liquid N0. 2 consisting of 9.5 parts of trimethylolmelamine, 9.9 parts of urea and 45.1 parts of water were prepared. A cotton cloth (240.5 g/m) was soaked therein with optional percentages of pick-up adjusted by a Mangler (a squeezing instrument) and was dried for 4.5 minutes at 85 C. and curing was performed for minutes at 140C. The cloth was then treated by heat, was soaped by being vigorously stirred for 20 minutes at 90C. with a liquor ratio of 50 using a water solution containing 0.25 Wt. of Na CO and 0.25 wt. of Maruseru soap (product of Nippon Yushi K.K., Nissan Maruseru Soap), and further was rinsed and dried for minutes at 40C. with a liquor ratio of 100.

The same flame resistance tests as in Practical Example 66 were executed. The pick-ups were 74.5 percent, 106.3 percent, 132.9 percent and 152.1 percent, the corresponding add-on percentages were, respectively, 20.4 percent, 30.1 percent, 38.9 percent and 45.3 percent. Only that having an add-on percentage of 45.3 percent passed the flame resistance test (namely, after flame seconds were less than 3 seconds, after glow seconds less than 5 seconds, and carbonization area less than 30 cm But even this one, when subjected to continuous washing times, could not pass the carbonization test. Also, this cloth had a rough feel.

Comparison Example 14 A soaking liquid consisting of parts of tris (1- Azin'dinyl) phosphine oxide:

15 parts of thiourea, 3 parts of polyethylene softening agents (Parmalin PN, product of Sanyo Kasei Kogyo K.l(.), 0.2 part of penetrant (Emulgen-8l0, product of Kao Atlas K.K.) and 56.8 parts of water was prepared. The cotton cloth to be treated (240.5 g/m) was soaked and optional percentages of pick-up, adjusted by a Mangler (a squeezing instrument), and was dried for 5 minutes at 80C. and curing was performed for 2 minutes at 160C. After that the cloth treated by heat was soaped by being vigorously stirred for 20 minutes at 90C. with a liquor ratio of 50 using a water solution containing 0.25 wt. of Na CO and 0.25 wt. Maruseru soap (product of Nippon Yushi K.l(., Nissan Maruseru Soap), and further it was rinsed and dried for 15 minutes at 40C. with a liquor ratio of 100. Then the same flame resistance tests as in Practical Example 66 were executed.

The pick-ups were 63.9 percent, 84.3 percent, 128.9 percent and 145.6 percent, the corresponding add-on percentages were, respectively, 18.0 percent, 27.3 percent, 42.8 percent and 49.6 percent. Only those cloths having add-on percentages of 42.8 percent and 49.6 percent passed the flame resistance tests. Moreover, even those having add-on percentages of 42.8 percent, when subjected to continuous washing 20 times as in Comparison Example 13, could not pass the after glow test. Also, these cloths had a very rough feel.

Comparison Example 15 A soaking liquid consisting of 30 parts of N- hydroxymethyl-3-(dimethylphosphono)propionamide:

8 parts of trimethylomelamine, 1 part of urea, 0.4 part of ammonium chloride, 0.2 part of penetrant (Emulgen-810, product of Kao Atlas K.K.) 2 parts of polyethylene softening agent (Parmalin PN, product of Sanyo Kasei Kogyo K.K.) and 58.4 parts of water, was prepared.

The cotton cloth to be treated (240.5 g/m) was soaked with optional percentages of pick-up adjusted by a Mangler (a squeezing instrument) and was dried for 5 minutes at C., and curing was performed for 4.5 minutes at 160C. After that, the cloth treated by heat was soaped by being vigorously stirred for 20 minutes at C. with a liquor ratio of 50 using a water solution containing 0.25 wt. of Na CO and 0.25 wt. of Maruseru soap (product of Nippon Yushi K.K., Nissan Maruseru Soap), and further it was rinsed and dried for 15 minutes at 40C. with a liquor ratio of 100. Then the same flame resistance tests as in Practical Example 66 were executed.

The pick-ups were 74.6 percent, 106.7 percent, 129.3 percent, and 155.4 percent. The corresponding add-0n percentages were, respectively, 18.9 percent, 27.9 percent, 27.4 percent, 34.3 percent, and 41.0 percent. Only those cloths having an add-on percentage of 34.3 percent and 41.0 percent passed the flame resistance tests. Moreover, even these, when subjected to continuous washings 20 times as in Comparison Example 13, could not pass the carbonization test. Also, these cloths had a rather rough feel.

Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention.

What is claimed as new and desired to be secured by Letters Patent is:

l. A method for flame proofing a fiber which comprises impregnating such fiber with a solution of an aziridinyl phosphine oxide compound selected from the group consisting of:

fiber to fix the aziridinyl phophine oxide compound onto the fiber.

2. The flame-proofing method according to claim 1, wherein the halogens of the halogenoalkyl group and halogenoalkylene group are respectively bromine or chlorine.

3. The flame-proofing method according to claim 1, wherein said hydrogenoalkyl group contains from two 'to three carbon atoms and the hydrogenoalkylene group contains one to four carbon atoms.

4. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound has sodium sulfonate group and an aqueous solution of the compound is applied to the fiber.

5. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound is dissolved in a solvent and is applied to the fiber in the form of a solution.

6. The flame-proofing method according to claim 5, wherein the organic solvent is an aliphatic solvent or aromatic solvent.

7. The flame-proofing method according to claim 1, wherein the fiber treated is selected from the group consisting of cotton, rayon, hemp, silk, wool, polyvinyl alcohol, polyacrylonitrile, polyester, polyvinylchloride, polyvinylidene chloride and polyamide.

8. The flame-proofing method according to claim 1, wherein the fiber is immersed in a solution of the aziridinyl phosphine oxide compound and a curing catalyst at 0C. to 60C., and the pick-up rate of the solution is 50 98 percent by weight based on the weight of the fiber.

9. The flame-proofing method according to claim 1, wherein the concentration of the flame-proofing agent is 5 60 percent by weight and the concentration of the curing catalyst is 1 30 g/l.

10. A flame-proofing method according to claim 1, wherein the impregnated fiber is dried at 30 C. and is cured at 50 150C.

11. The flame-proofing method according to claim 1, wherein said acidic curing catalyst is ammonium chloride, monobasic ammonium phosphate, dibasic ammonium phosphate, ammonium borofluoride, zinc borofluoride or zinc nitrate.

12. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound is: 

2. The flame-proofing method according to claim 1, wherein the halogens of the halogenoalkyl group and halogenoalkylene group are respectively bromine or chlorine.
 3. The flame-proofing method according to claim 1, wherein said hydrogenoalkyl group contains from two to three carbon atoms and the hydrogenoalkylene group contains one to four carbon atoms.
 4. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound has sodium sulfonate group and an aqueous solution of the compound iS applied to the fiber.
 5. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound is dissolved in a solvent and is applied to the fiber in the form of a solution.
 6. The flame-proofing method according to claim 5, wherein the organic solvent is an aliphatic solvent or aromatic solvent.
 7. The flame-proofing method according to claim 1, wherein the fiber treated is selected from the group consisting of cotton, rayon, hemp, silk, wool, polyvinyl alcohol, polyacrylonitrile, polyester, polyvinylchloride, polyvinylidene chloride and polyamide.
 8. The flame-proofing method according to claim 1, wherein the fiber is immersed in a solution of the aziridinyl phosphine oxide compound and a curing catalyst at 0*C. to 60*C., and the pick-up rate of the solution is 50 - 98 percent by weight based on the weight of the fiber.
 9. The flame-proofing method according to claim 1, wherein the concentration of the flame-proofing agent is 5 - 60 percent by weight and the concentration of the curing catalyst is 1 - 30 g/l.
 10. A flame-proofing method according to claim 1, wherein the impregnated fiber is dried at 30* - 150*C. and is cured at 50* -150*C.
 11. The flame-proofing method according to claim 1, wherein said acidic curing catalyst is ammonium chloride, monobasic ammonium phosphate, dibasic ammonium phosphate, ammonium borofluoride, zinc borofluoride or zinc nitrate.
 12. The flame-proofing method according to claim 1, wherein the aziridinyl phosphine oxide compound is: 